[Federal Register Volume 64, Number 244 (Tuesday, December 21, 1999)]
[Rules and Regulations]
[Pages 71304-71317]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-32760]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[AZ 012-FIP; FRL-6511-3]
RIN 2060-AI54
Revision to Promulgation of Federal Implementation Plan for
Arizona--Maricopa Nonattainment Area; PM-10
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: Under the authority of section 110(c)(1) of the Clean Air Act
(CAA or ``the Act''), EPA is finalizing proposed amendments to the
moderate area federal implementation plan (FIP) for the Phoenix PM-10
nonattainment area. These amendments modify the fugitive dust rule to
add or replace certain test methods and allow alternative control
measures (ACMs) to be implemented without prior EPA approval. For the
convenience of readers, the entire FIP rule is reprinted in this
publication.
DATES: This action is effective on January 20, 2000.
ADDRESSES: A copy of docket No. A-98-42 containing material relevant to
this final action, including EPA's responses to comments received on
the proposed amendments, is available for review at: EPA Region 9, Air
Division, 75 Hawthorne Street, San Francisco, CA 94105. Interested
persons may make an appointment with Eleanor Kaplan (415) 744-1159 to
inspect the docket at EPA's San Francisco office on weekdays between 9
a.m. and 4 p.m.
A copy of the docket No. A-98-42 is also available to review at the
Arizona Department of Environmental Quality, Library, 3033 N. Central
Avenue, Phoenix, Arizona 85012. (602) 207-2217.
Electronic Availability: This document is also available as an
electronic file on EPA's Region 9 Air Web Page at http://www.epa.gov/
region09/air.
FOR FURTHER INFORMATION CONTACT: Karen Irwin (415) 744-1903.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Background
II. Summary of Final Action on Proposed Revisions
A. Test Methods
1. Silt Content Test Method
2. Visible Crust Test Method
3. Standing Vegetation Test Method Density Procedure
B. Alternative Control Measures
III. Unpaved Roads
IV. Agency Responses to Comments
V. Text Corrections to the Final Rule
VI. Administrative Requirements
A. Executive Order 12866
B. Executive Order 13045
C. Executive Order 13084
D. Executive Order 13132
E. Regulatory Flexibility Analysis
F. Unfunded Mandates Reform Act (UMRA)
G. Paperwork Reduction Act
H. National Technology Transfer and Advancement Act (NTTAA)
I. Submission to Congress and the General Accounting Office
J. Petitions for Judicial Review
I. Background
On August 3, 1998 (63 FR 41326), EPA finalized a FIP for the
Phoenix PM-10 nonattainment area (the ``final FIP''). Readers should
refer to 63 FR 41326 for details of the history and contents of the
final FIP.
The final FIP includes a fugitive dust rule to control PM-10
emissions from vacant lots, unpaved parking lots and unpaved roads
codified at 40 CFR 52.128 (63 FR 41326, 41350), hereafter referred to
as ``the final FIP rule''.1 EPA subsequently proposed
specific revisions related to the test methods, ACMs, and unpaved road
requirements of the final FIP rule (64 FR 3263, January 21, 1999). EPA
accepted comments on the proposed amendments through March 8, 1999. EPA
is now finalizing action on all but one of the proposed amendments and
re-publishing the final FIP fugitive dust rule in its entirety.
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\1\ EPA promulgated the final FIP rule as part of its court-
ordered obligation to provide for the implementation of Reasonably
Available Control Measures (RACM) (required by section 189(a)(1)(C)
of the Clean Air Act) in the Phoenix PM-10 nonattainment area.
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A detailed discussion of the FIP rule revisions proposed by EPA can
be found in 64 FR 3263, January 1999. EPA proposed to add a silt
content test method for unpaved roads and unpaved parking lots, add a
new visible crust test method or replace the visible crust test method
for vacant lots, add a procedure for measuring the density of standing
vegetation to the standing vegetation test method, include coverage of
privately owned unpaved roads that are privately maintained or not
maintained,2 and allow ACMs to be implemented without prior
EPA approval.
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\2\ Note: the FIP rule as finalized in August 1998 includes
coverage of privately owned unpaved roads that are publicly
maintained; EPA's proposal in January 1999 to include privately
owned roads that are privately maintained or not maintained has no
bearing on existing FIP rule coverage of privately owned, publicly
maintained unpaved roads.
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[[Page 71305]]
II. Summary of Final Action on Proposed Revisions
A. Test Methods
1. Silt Content Test Method
The final FIP rule contains an opacity standard of twenty (20)
percent, or Ringlemann 1, for unpaved roads and unpaved parking lots.
Compliance with this standard is to be tested using visible emissions
test methods included in the final Phoenix FIP rule.3 EPA
proposed an additional, new test method for measuring silt
content.4
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\3\ Reference Method 9 (40 CFR part 60, appendix A) and Methods
203A and 203C. Appendix A.I. to Sec. 52.128 (63 FR 41326, 41353-
41355).
\4\ 64 FR 3263, 3267-3268.
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EPA solicited comments on this additional test method and whether
or not to retain the existing opacity test method in the final FIP
rule. EPA received no comments suggesting that the existing opacity
test method be eliminated from the FIP rule. In this final action, EPA
has added the silt content test method into the FIP rule and retained
the opacity test method. Therefore, sources subject to the FIP rule
will need to comply with both a silt content standard and an opacity
standard.
Also, EPA received public comments suggesting that silt loading be
taken into account. In this final action, EPA has included a silt
loading value in the silt content test method, below which a source may
be deemed in compliance with the FIP rule. Text changes to accommodate
this addition occur in paragraph (b)(16) and in Appendix A, I.B of the
final amendments.
Furthermore, EPA has clarified the following items from the
proposed test method text:
Samples should be collected to a depth of approximately 1
centimeter or until a hard subsurface is reached, whichever occurs
first.
If sieving is simplified by combining three samples, each
sample should weigh within one ounce of the other two samples. (EPA's
contractor clarified that samples must be of approximately the same
weight in order to ensure technical accuracy if they are combined.)
5
\5\ Chatten Cowherd, MRI Research Institute in Kansas City,
Missouri, January 1999.
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EPA has corrected the following two items from the proposed test method
text:
An incorrect reference to collector pan material as silt
fraction has been eliminated.
A printing error in the AP-42 silt content test method
with respect to the method's equation to calculate percent silt
content.
2. Visible Crust Test Method
The final FIP rule's test method for measuring visible crust
thickness on vacant lots involved breaking off a piece of crust,
checking whether the crust crumbles easily and measuring its thickness
with a ruler.6 EPA proposed an alternative method to
determine the sufficiency of a visible crust.7 The
alternative test method involves dropping a small steel ball from a
height of one foot in select one square foot areas and checking to see
whether the ball penetrates the surface or causes loose grains to
appear. Public comments received support the alternative method. In
this final action, EPA has replaced the earlier visible crust thickness
test method with the alternative visible crust test method. This
required renumbering of the proposed text 8 for consistency
with the numbering of other vacant lot test methods. Also, EPA has
modified the text to allow the weight of the ball used in the test
method to range from 16 to 17 grams, as opposed to an exact weight of
16.33 grams.
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\6\ 63 FR 41324, 41355.
\7\ 64 FR 3263, 3268-3269.
\8\ 63 FR 3263, 3268.
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3. Standing Vegetation Test Method Density Procedure
The final FIP rule contains a test method for standing
vegetation.9 EPA proposed to add a vegetation density
procedure involving the use of a grid with one inch or half-inch
squares to help ensure that various vegetative structures can be
assessed accurately and consistently.10 Public comments
received support the inclusion of the vegetation density procedure in
the standing vegetation test method. In this final action, EPA has
added the density procedure into the final FIP rule. EPA also made two
minor text corrections to the proposed test method which are enumerated
in the Technical Support Document associated with this action, which
can be found in Docket No. A-98-42.
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\9\ 63 FR 41326, 41356.
\10\ 64 FR 3263, 3269-3271. The procedure was provided to EPA by
Larry Hagen, Agricultural Engineer, United States Department of
Agriculture, Wind Erosion Research Unit, 2004 Throckmortion Hall,
Kansas State University, Manhatten, Kansas 66506.
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B. Alternative Control Measures
In the final FIP rule (August 1998), ACMs are allowed provided that
they are submitted to EPA and receive EPA approval.11 ACMs
are any RACM not specifically listed in the rule that can meet the
rule's stabilization standards for each source category.12
EPA proposed to amend the final FIP rule such that ACMs would not
require prior EPA approval.13 In today's action, EPA has
accordingly eliminated the final FIP rule requirement that ACMs receive
prior EPA approval.
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\11\ 63 FR 41326, 41352.
\12\ The ACM provisions of the rule do not otherwise authorize
any modification of the FIP rule's requirements.
\13\ 64 FR 3263, 3267.
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III. Unpaved Roads
The final FIP rule contains requirements to control fugitive dust
from unpaved roads that are publicly owned and/or operated (i.e.,
maintained). This includes privately owned roads that are publicly
maintained. EPA proposed to include in the FIP rule unpaved privately
owned roads that are privately maintained or not maintained. EPA is not
taking final action at this time on the proposed amendments to the
unpaved road requirements of the final FIP rule. The Maricopa
Association of Governments (MAG) recently announced its intent to pave
or otherwise control all unpaved roads located in the PM-10
nonattainment area with traffic levels that meet or exceed 130 average
daily trips.14 EPA believes that the County's action may
supersede the need for EPA to control additional unpaved roads as
specified in the proposed FIP revision, and thus is not taking action
on the proposed revision at this time.
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\14\ Memorandum from Lindy Bauer, MAG, to Members of the MAG Air
Quality Planning Team, November 30, 1999, summarizing the MAG
Transportation Review Committee's funding recommendations presented
on November 23, 1999.
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IV. Agency Responses to Comments
A 45-day public comment period was provided in 64 FR 3263. EPA
received several comments on the proposed FIP rule revisions and
responds to the most significant below. EPA has responded to all
comments associated with this final action in the Technical Support
Document, which can be found in Docket No. A-98-42.
Comment: Maricopa County Environmental Services Division (MCESD)
comments that by itself, the silt content of the surface material on an
unpaved road is a unidimensional parameter and does not indicate
whether or not the road is stabilized. It is the silt loading value
which provides an indicator of stabilization as it estimates the amount
of fine particulate per surface area which may become airborne. The
proposed test method should be modified to derive silt loading in place
of silt content.
[[Page 71306]]
Response: EPA has modified the test method to include a silt
loading parameter, such that surfaces with less than 0.33 oz/ft.\3\
silt loading will be considered stable under the FIP rule. However, EPA
has retained the silt content standards of 6 percent for unpaved roads
and 8 percent for unpaved parking lots when silt loading is greater
than or equal to 0.33 oz/ft \2\
Comment: MCESD, Maricopa County Department of Transportation
(MCDOT) and Arizona Department of Environmental Quality (ADEQ) comment
on the benefits associated with retaining the opacity test method in
the FIP rule while adding a silt content test method. With respect to
visible crust test methods, however, MCESD and ADEQ comment that EPA
should replace (i.e., not retain) the visible crust test currently
found in the FIP rule with the proposed ``drop ball'' visible crust
test. Arizona Center for Law in the Public Interest (ACLPI) comments
that they support the use of the most accurate test methods available,
however, test methods should not be replaced where the superiority of
the replacement tests has not been established; requiring both existing
and proposed tests, at least for a certain time period, would not be
unduly cumbersome or expensive to the regulated community, and this
would also allow EPA to compare the relative value and accuracy of the
two sets of tests.
Response: EPA has retained the opacity standard in the FIP rule,
while adding a new test method for measuring silt content. Retaining
both the opacity and silt content standards and test methods in the
final FIP rule will provide greater flexibility for qualified persons
to conduct compliance testing of fugitive dust sources and will allow
opportunities to compare the relative value and accuracy of the two
tests.
With respect to visible crust test methods, EPA has replaced the
former visible crust test with the proposed ``drop ball'' visible crust
test. EPA conducted field testing of both the visible crust test method
in the final FIP rule and the proposed ``drop ball'' visible crust test
method. Field testing showed that the proposed ``drop ball'' test
method is easier to conduct, more accurately repeatable by various
parties, and more indicative of whether a sufficiently stabilizing
crust exists. To ensure the use of a superior method, EPA is replacing
the test method in the final FIP rule with the ``drop ball'' test
method. (Interested parties should note that the test method for
threshold friction velocity promulgated in the final FIP rule can also
be used to determine source compliance where some visible crusting is
present.)
Comment: ADEQ comments that adding the vegetative density procedure
to the current test method would clarify the method and produce more
accurate results when performed by different individuals.
Response: EPA has added the vegetative density procedure to the
standing vegetation test method.
Comment: ADEQ comments that they support eliminating the
requirement to submit ACMs to EPA because implementation costs will
decrease since parties will not need to commit time and resources to
submit ACMs to EPA and wait for approval before utilizing them. ACLIPI,
however, comments that they strongly object to the implementation of
ACMs without EPA approval because without such approval, ACMs will
inevitably become ``least effective control measures''.
Response: EPA has eliminated the requirement to submit ACMs to EPA
for approval. Since the FIP rule contains standards and test methods
which indicate whether a surface is stabilized, owners/operators can be
allowed flexibility as to the type of control measure applied as long
as the control measure results in a stabilized surface. The elimination
of the requirement to submit ACMs for prior EPA approval does not
lessen the owners'/operators' responsibility to implement control
measures effectively on the sources subject to the rule. In fact, by
emphasizing the intended result, as opposed to the type of control, EPA
hopes to increase owners'/operators' understanding that their
responsibility under the FIP rule will remain until a source is
controlled, even if the owner/operator inadequately implements a
control measure or implements an ineffective control measure. If
applied, ACMs must meet the minimum standards established by the FIP
rule, therefore, requiring that ACMs be submitted to EPA for approval
would result in unnecessary administrative burden.
V. Text Corrections to the Final Rule
In addition to finalizing the proposed rule amendments, EPA is
incorporating a few minor corrections to final FIP rule text at 40 CFR
52.128. These are enumerated in the Technical Support Document
associated with this action, which can be found in Docket No. A-98-42.
VI. Administrative Requirements
A. Executive Order 12866
Under Executive Order 12866, 58 FR 51735 (October 4, 1993), the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to Office of Management and Budget (OMB) review
and the requirements of the Executive Order. The Order defines
``significant regulatory action'' as one that is likely to result in a
rule that may:
(1) have an annual effect on the economy of $100 million or more
or adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local or tribal governments or
communities;
(2) create a serious inconsistency or otherwise interfere with
an action taken or planned by another agency;
(3) materially alter the budgetary impact of entitlements,
grants, user fees, or loan programs or the rights and obligations of
recipients thereof; or
(4) raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Due to potential novel policy issues this action is considered a
significant regulatory action and therefore must be reviewed by OMB.
Changes made in response to OMB suggestions or recommendations will be
documented in the public record.
B. Executive Order 13045
Protection of Children from Environmental Health Risks and Safety
Risks (62 FR 19885, April 23, 1997), applies to any rule that: (1) Is
determined to be ``economically significant'' as defined under
Executive Order 12866, and (2) concerns an environmental health or
safety risk that EPA has reason to believe may have a disproportionate
effect on children. If the regulatory action meets both criteria, the
Agency must evaluate the environmental health or safety effects of the
planned rule on children, and explain why the planned regulation is
preferable to other potentially effective and reasonably feasible
alternatives considered by the Agency.
This rule is not subject to Executive Order 13045 because it does
not involve decisions intended to mitigate environmental health or
safety risks.
C. Executive Order 13084
Under Executive Order 13084, EPA may not issue a regulation that is
not required by statute, that significantly affects or uniquely affects
the communities of Indian tribal governments, and that imposes
substantial direct compliance costs on those communities, unless the
Federal government provides the funds necessary to pay the direct
compliance costs incurred by the tribal
[[Page 71307]]
governments. If EPA complies by consulting, Executive Order 13084
requires EPA to provide to the Office of Management and Budget, in a
separately identified section of the preamble to the rule, a
description of the extent of EPA's prior consultation with
representatives of affected tribal governments, a summary of the nature
of their concerns, and a statement supporting the need to issue the
regulation. In addition, Executive Order 13084 requires EPA to develop
an effective process permitting elected and other representatives of
Indian tribal governments ``to provide meaningful and timely input in
the development of regulatory policies on matters that significantly or
uniquely affect their communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. This action does not involve
or impose any requirements that affect Indian Tribes. Accordingly, the
requirements of section 3(b) of Executive Order 13084 do not apply to
this rule.
D. Executive Order 13132
Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.'' Under
Executive Order 13132, EPA may not issue a regulation that has
federalism implications, that imposes substantial direct compliance
costs, and that is not required by statute, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by State and local governments, or EPA consults with
State and local officials early in the process of developing the
proposed regulation. EPA also may not issue a regulation that has
federalism implications and that preempts State law unless the Agency
consults with State and local officials early in the process of
developing the proposed regulation.
If EPA complies by consulting, Executive Order 13132 requires EPA
to provide to the Office of Management and Budget (OMB), in a
separately identified section of the preamble to the rule, a federalism
summary impact statement (FSIS). The FSIS must include a description of
the extent of EPA's prior consultation with State and local officials,
a summary of the nature of their concerns and the agency's position
supporting the need to issue the regulation, and a statement of the
extent to which the concerns of State and local officials have been
met. Also, when EPA transmits a draft final rule with federalism
implications to OMB for review pursuant to Executive Order 12866, EPA
must include a certification from the agency's Federalism Official
stating that EPA has met the requirements of Executive Order 13132 in a
meaningful and timely manner.
This final rule will not have substantial direct effects on the
States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among the
various levels of government, as specified in Executive Order 13132.
The revisions finalized in this rulemaking concern test methods and
flexibility for alternative compliance. Thus, the requirements of
section 6 of the Executive Order do not apply to this rule.
E. Regulatory Flexibility Analysis
1. Regulatory Flexibility Act Requirements
Under the Regulatory Flexibility Act (RFA), 5 U.S.C. 600 et seq.,
EPA must prepare a regulatory flexibility analysis assessing the impact
of any proposed or final rule on small entities. Alternatively, EPA may
certify that the rule will not have a significant impact on a
substantial number of small entities. Small entities include small
businesses, small not-for-profit enterprises, and government entities
with jurisdiction over populations of less than 50,000.
For the purposes of this inquiry, as it applies to the proposed
amendments to the federal fugitive dust rule (40 CFR Sec. 52.128), EPA
is assuming that the affected or potentially affected sources
constitute ``small entities'' as defined by the RFA.
A detailed discussion of the RFA analysis for the final FIP is
found in section V.B. at 63 FR 41326. In general, the finalized
amendments to the final FIP fugitive dust rule are intended to provide
more flexibility in complying with the FIP rule and to improve the test
methods as they currently exist in the rule. Thus, EPA believes that
the amendments will not change the final FIP RFA analysis, except
possibly to have a lesser impact on small entities.
2. RFA Analysis
a. Finalized Amendments to Federal Rule for Unpaved Roads, Unpaved
Parking Lots and Vacant Lots
EPA believes that the finalized test method amendments will provide
either more flexibility or an improved procedure for determining
compliance with the FIP fugitive dust rule. The silt content test
method will allow persons who are not certified in visible emissions
training to test the stability of an unpaved road or unpaved parking
lot by using an alternative method to the opacity test method. EPA
plans to ensure that the necessary sieve units are available for loan
by local entities to regulated sources. Also, the newly added visible
crust test method accomplishes the same objective as the previous
visible crust test method yet is more practical and can be accurately
repeated by various parties. The additional procedure to assist parties
in measuring frontal silhouette area of various vegetative structures
is merely intended to address circumstances that may arise in the field
which are not addressed in the final FIP rule. Finally, eliminating the
requirement for EPA approval of ACMs increases the rule's flexibility
for source owners/operators and reduces the paperwork burden of the
rule.
b. Certification
For reasons discussed above, EPA has determined that it is not
necessary to prepare a regulatory flexibility analysis in connection
with the final rule amendments. After consideration of the economic
impacts of today's final rule amendments on small entities, I hereby
certify that the final rule will not have a significant economic impact
on a substantial number of small entities.
F. Unfunded Mandates Reform Act (UMRA)
Under Section 202 of the Unfunded Mandates Reform Act of 1995
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA
must prepare a budgetary impact statement to accompany any proposed or
final rule that includes a Federal mandate that may result in estimated
costs to State, local, or tribal governments in the aggregate; or to
private sector, of $100 million or more. Under Section 205, EPA must
select the most cost-effective and least burdensome alternative that
achieves the objectives of the rule and is consistent with statutory
requirements. Section 203 requires EPA to establish a plan for
informing and advising any small governments that
[[Page 71308]]
may be significantly or uniquely impacted by the rule.
A detailed discussion of the UMRA requirements and how they are
addressed can be found in section V.C. of the final FIP rulemaking (63
FR 41326). As explained above, today's finalized amendments to the
final FIP fugitive dust rule are intended to provide more flexibility
in complying with the FIP rule and to improve the test methods
currently in the rule. Thus, EPA believes that the amendments will not
change the final FIP UMRA analysis, except possibly to have a lesser
impact on most regulated entities.
G. Paperwork Reduction Act
The finalized test method and ACM amendments do not impact the
information collection request analysis for the final FIP (EPA ICR
1855.02). The final FIP (63 FR 41326) provides more information on the
information collection request requirements.
H. National Technology Transfer and Advancement Act (NTTAA)
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law No. 104-113, Sec. 12(d) (15 U.S.C.
272 note) directs EPA to use voluntary consensus standards in its
regulatory activities unless to do so would be inconsistent with
applicable law or otherwise impractical. Voluntary consensus standards
are technical standards (e.g., materials specifications, test methods,
sampling procedures, and business practices) that are developed or
adopted by voluntary consensus standards bodies. The NTTAA directs EPA
to provide Congress, through OMB, explanations when the Agency decides
not to use available and applicable voluntary consensus standards.
In this action, EPA has incorporated voluntary consensus standards
where feasible [See language for Appendix A to Sec. 52.128, I.B(iv)].
However, in most cases there are no applicable technical standards or
field procedures specifically designed for the source categories at
hand. OMB has reviewed and concurred on the applicable technical
standards finalized in this revision.
I. Submission to Congress and the General Accounting Office
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. This rule is not a
``major'' rule as defined by 5 U.S.C. 804(2).
J. Petitions for Judicial Review
Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by February 22, 2000. Filing a
petition for reconsideration by the Administrator of this final rule
does not affect the finality of this rule for the purposes of judicial
review nor does it extend the time within which a petition for judicial
review may be filed, and shall not postpone the effectiveness of such
rule or action. This action may not be challenged later in proceedings
to enforce its requirements. (See section 307(b)(2).)
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Intergovernmental
relations, Particulate matter.
Dated: December 13, 1999.
Carol M. Browner,
Administrator.
For the reasons set forth in the preamble, part 52, chapter I,
title 40 of the Code of Federal Regulations is amended as follows:
PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS
1. The authority citation for part 52 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
Subpart D--Arizona
2. Section 52.128 is revised as follows:
Sec. 52.128 Rule for unpaved parking lots, unpaved roads and vacant
lots.
(a) General. (1) Purpose. The purpose of this section is to limit
the emissions of particulate matter into the ambient air from human
activity on unpaved parking lots, unpaved roads and vacant lots.
(2) Applicability. The provisions of this section shall apply to
owners/operators of unpaved roads, unpaved parking lots and vacant lots
and responsible parties for weed abatement on vacant lots in the
Phoenix PM-10 nonattainment area. This section does not apply to
unpaved roads, unpaved parking lots or vacant lots located on an
industrial facility, construction, or earth-moving site that has an
approved permit issued by Maricopa County Environmental Services
Division under Rule 200, Section 305, Rule 210 or Rule 220 containing a
Dust Control Plan approved under Rule 310 covering all unpaved parking
lots, unpaved roads and vacant lots. This section does not apply to the
two Indian Reservations (the Salt River Pima-Maricopa Indian Community
and the Fort McDowell Mojave-Apache Indian Community) and a portion of
a third reservation (the Gila River Indian Community) in the Phoenix
PM-10 nonattainment area. Nothing in this definition shall preclude
applicability of this section to vacant lots with disturbed surface
areas due to construction, earth-moving, weed abatement or other dust
generating operations which have been terminated for over eight months.
(3) The test methods described in Appendix A of this section shall
be used when testing is necessary to determine whether a surface has
been stabilized as defined in paragraph (b)(16) of this section.
(b) Definitions. (1) Average daily trips (ADT)--The average number
of vehicles that cross a given surface during a specified 24-hour time
period as determined by the Institute of Transportation Engineers Trip
Generation Report (6th edition, 1997) or tube counts.
(2) Chemical/organic stabilizer--Any non-toxic chemical or organic
dust suppressant other than water which meets any specifications,
criteria, or tests required by any federal, state, or local water
agency and is not prohibited for use by any applicable law, rule or
regulation.
(3) Disturbed surface area--Any portion of the earth's surface, or
materials placed thereon, which has been physically moved, uncovered,
destabilized, or otherwise modified from its undisturbed natural
condition, thereby increasing the potential for emission of fugitive
dust.
(4) Dust suppressants--Water, hygroscopic materials, solution of
water and chemical surfactant, foam, or non-toxic chemical/organic
stabilizers not prohibited for use by any applicable law, rule or
regulation, as a treatment material to reduce fugitive dust emissions.
(5) EPA--United States Environmental Protection Agency, Region IX,
75 Hawthorne Street, San Francisco, California 94105.
[[Page 71309]]
(6) Fugitive dust--The particulate matter entrained in the ambient
air which is caused from man-made and natural activities such as, but
not limited to, movement of soil, vehicles, equipment, blasting, and
wind. This excludes particulate matter emitted directly from the
exhaust of motor vehicles and other internal combustion engines, from
portable brazing, soldering, or welding equipment, and from
piledrivers.
(7) Lot--A parcel of land identified on a final or parcel map
recorded in the office of the Maricopa County recorder with a separate
and distinct number or letter.
(8) Low use unpaved parking lot--A lot on which vehicles are parked
no more than thirty-five (35) days a year, excluding days where the
exemption in paragraph (c)(2) of this section applies.
(9) Motor vehicle--A self-propelled vehicle for use on the public
roads and highways of the State of Arizona and required to be
registered under the Arizona State Uniform Motor Vehicle Act, including
any non-motorized attachments, such as, but not limited to, trailers or
other conveyances which are connected to or propelled by the actual
motorized portion of the vehicle.
(10) Off-road motor vehicle--any wheeled vehicle which is used off
paved roadways and includes but is not limited to the following:
(i) Any motor cycle or motor-driven cycle;
(ii) Any motor vehicle commonly referred to as a sand buggy, dune
buggy, or all terrain vehicle.
(11) Owner/operator--any person who owns, leases, operates,
controls, maintains or supervises a fugitive dust source subject to the
requirements of this section.
(12) Paving--Applying asphalt, recycled asphalt, concrete, or
asphaltic concrete to a roadway surface.
(13) Phoenix PM-10 nonattainment area--such area as defined in 40
CFR 81.303, excluding Apache Junction.
(14) PM-10--Particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers as measured by reference or
equivalent methods that meet the requirements specified for PM-10 in 40
CFR part 50, Appendix J.
(15) Reasonably available control measures (RACM)--Techniques used
to prevent the emission and/or airborne transport of fugitive dust and
dirt.
(16) Stabilized surface--(i) Any unpaved road or unpaved parking
lot surface where:
(A) Any fugitive dust plume emanating from vehicular movement does
not exceed 20 percent opacity as determined in section I.A of Appendix
A of this section; and
(B) Silt loading (weight of silt per unit area) is less than 0.33
ounces per square foot as determined by the test method in section I.B
of Appendix A of this section OR where silt loading is greater than or
equal to 0.33 ounces per square foot and silt content does not exceed
six (6) percent for unpaved road surfaces or eight (8) percent for
unpaved parking lot surfaces as determined by the test method in
section I.B of Appendix A of this section.
(ii) Any vacant lot surface with:
(A) A visible crust which is sufficient as determined in section
II.1 of Appendix A of this section;
(B) A threshold friction velocity (TFV), corrected for non-erodible
elements, of 100 cm/second or higher as determined in section II.2 of
Appendix A of this section;
(C) Flat vegetation cover equal to at least 50 percent as
determined in section II.3 of Appendix A of this section;
(D) Standing vegetation cover equal to or greater than 30 percent
as determined in section II.4 of Appendix A of this section; or
(E) Standing vegetation cover equal to or greater than 10 percent
as determined in section II.4 of Appendix A of this section where
threshold friction velocity, corrected for non-erodible elements, as
determined in section II.2 of Appendix A of this section is equal to or
greater than 43 cm/second.
(17) Unpaved parking lot--A privately or publicly owned or operated
area utilized for parking vehicles that is not paved and is not a Low
use unpaved parking lot.
(18) Unpaved road--Any road, equipment path or driveway used by
motor vehicles or off-road motor vehicles that is not paved which is
open to public access and owned/operated by any federal, state, county,
municipal or other governmental or quasi-governmental agencies.
(19) Urban or suburban open area--An unsubdivided or undeveloped
tract of land adjoining a residential, industrial or commercial area,
located on public or private property.
(20) Vacant lot--A subdivided residential, industrial,
institutional, governmental or commercial lot which contains no
approved or permitted buildings or structures of a temporary or
permanent nature.
(c) Exemptions. The following requirements in paragraph (d) of this
section do not apply:
(1) In paragraphs (d)(1), (d)(2) and (d)(4)(iii) of this section:
Any unpaved parking lot or vacant lot 5,000 square feet or less.
(2) In paragraphs (d)(1) and (d)(2) of this section: Any unpaved
parking lot on any day in which ten (10) or fewer vehicles enter.
(3) In paragraphs (d)(4)(i) and (d)(4)(ii) of this section: Any
vacant lot with less than 0.50 acre (21,780 square feet) of disturbed
surface area(s).
(4) In paragraph (d) of this section: Non-routine or emergency
maintenance of flood control channels and water retention basins.
(5) In paragraph (d) of this section: Vehicle test and development
facilities and operations when dust is required to test and validate
design integrity, product quality and/or commercial acceptance. Such
facilities and operations shall be exempted from the provisions of this
section only if such testing is not feasible within enclosed
facilities.
(6) In paragraph (d)(4)(i) of this section: Weed abatement
operations performed on any vacant lot or property under the order of a
governing agency for the control of a potential fire hazard or
otherwise unhealthy condition provided that mowing, cutting, or another
similar process is used to maintain weed stubble at least three (3)
inches above the soil surface. This includes the application of
herbicides provided that the clean-up of any debris does not disturb
the soil surface.
(7) In paragraph (d)(4)(i) of this section: Weed abatement
operations that receive an approved Earth Moving permit under Maricopa
County Rule 200, Section 305 (adopted 11/15/93).
(d) Requirements. (1) Unpaved parking lots. Any owners/operators of
an unpaved parking lot shall implement one of the following RACM on any
surface area(s) of the lot on which vehicles enter and park.
(i) Pave; or
(ii) Apply chemical/organic stabilizers in sufficient concentration
and frequency to maintain a stabilized surface; or
(iii) Apply and maintain surface gravel uniformly such that the
surface is stabilized; or
(iv) Apply and maintain an alternative control measure such that
the surface is stabilized, provided that the alternative measure is not
prohibited under paragraph (b)(2) or (b)(4) of this section.
(2) Any owners/operators of a low use unpaved parking lot as
defined in paragraph (b)(8) of this section shall implement one of the
RACM under paragraph (d)(1) of this section on any day(s) in which over
100 vehicles enter the lot, such that the surface area(s) on which
vehicles enter and park is/are
[[Page 71310]]
stabilized throughout the duration of time that vehicles are parked.
(3) Unpaved roads. Any owners/operators of existing unpaved roads
with ADT volumes of 250 vehicles or greater shall implement one of the
following RACM along the entire surface of the road or road segment
that is located within the Phoenix non-attainment area by June 10,
2000:
(i) Pave; or
(ii) Apply chemical/organic stabilizers in sufficient concentration
and frequency to maintain a stabilized surface; or
(iii) Apply and maintain surface gravel uniformly such that the
surface is stabilized; or
(iv) Apply and maintain an alternative control measure such that
the surface is stabilized, provided that the alternative measure is not
prohibited under paragraph (b)(2) or (b)(4) of this section.
(4) Vacant lots. The following provisions shall be implemented as
applicable.
(i) Weed abatement. No person shall remove vegetation from any
vacant lot by blading, disking, plowing under or any other means
without implementing all of the following RACM to prevent or minimize
fugitive dust.
(A) Apply a dust suppressant(s) to the total surface area subject
to disturbance immediately prior to or during the weed abatement.
(B) Prevent or eliminate material track-out onto paved surfaces and
access points adjoining paved surfaces.
(C) Apply a dust suppressant(s), gravel, compaction or alternative
control measure immediately following weed abatement to the entire
disturbed surface area such that the surface is stabilized.
(ii) Disturbed surfaces. Any owners/operators of an urban or
suburban open area or vacant lot of which any portion has a disturbed
surface area(s) that remain(s) unoccupied, unused, vacant or
undeveloped for more than fifteen (15) calendar days shall implement
one of the following RACM within sixty (60) calendar days following the
disturbance.
(A) Establish ground cover vegetation on all disturbed surface
areas in sufficient quantity to maintain a stabilized surface; or
(B) Apply a dust suppressant(s) to all disturbed surface areas in
sufficient quantity and frequency to maintain a stabilized surface; or
(C) Restore to a natural state, i.e. as existing in or produced by
nature without cultivation or artificial influence, such that all
disturbed surface areas are stabilized; or
(D) Apply and maintain surface gravel uniformly such that all
disturbed surface areas are stabilized; or
(E) Apply and maintain an alternative control measure such that the
surface is stabilized, provided that the alternative measure is not
prohibited under paragraph (b)(2) or (b)(4) of this section.
(iii) Motor vehicle disturbances. Any owners/operators of an urban
or suburban open area or vacant lot of which any portion has a
disturbed surface area due to motor vehicle or off-road motor vehicle
use or parking, notwithstanding weed abatement operations or use or
parking by the owner(s), shall implement one of the following RACM
within 60 calendar days following the initial determination of
disturbance.
(A) Prevent motor vehicle and off-road motor vehicle trespass/
parking by applying fencing, shrubs, trees, barriers or other effective
measures; or
(B) Apply and maintain surface gravel or chemical/organic
stabilizer uniformly such that all disturbed surface areas are
stabilized.
(5) Implementation date of RACM. All of the requirements in
paragraph (d) of this section shall be effective eight (8) months from
September 2, 1998. For requirements in paragraph (d)(4)(ii) and
(d)(4)(iii) of this section, RACM shall be implemented within eight (8)
months from September 2, 1998, or within 60 calendar days following the
disturbance, whichever is later.
(e) Monitoring and records. (1) Any owners/operators that are
subject to the provisions of this section shall compile and retain
records that provide evidence of control measure application,
indicating the type of treatment or measure, extent of coverage and
date applied. For control measures involving chemical/organic
stabilization, records shall also indicate the type of product applied,
vendor name, label instructions for approved usage, and the method,
frequency, concentration and quantity of application.
(2) Copies of control measure records and dust control plans along
with supporting documentation shall be retained for at least three
years.
(3) Agency surveys. (i) EPA or other appropriate entity shall
conduct a survey of the number and size (or length) of unpaved roads,
unpaved parking lots, and vacant lots subject to the provisions of this
section located within the Phoenix PM-10 nonattainment area beginning
no later than 365 days from September 2, 1998.
(ii) EPA or other appropriate entity shall conduct a survey at
least every three years within the Phoenix PM-10 nonattainment area
beginning no later than 365 days from September 2, 1998, which
includes:
(A) An estimate of the percentage of unpaved roads, unpaved parking
lots, and vacant lots subject to this section to which RACM as required
in this section have been applied; and
(B) A description of the most frequently applied RACM and estimates
of their control effectiveness.
Appendix A to Sec. 52.128--Test Methods To Determine Whether A Surface
Is Stabilized
I. Unpaved Roads and Unpaved Parking Lots
A. Opacity Observations
Conduct opacity observations in accordance with Reference Method
9 (40 CFR Part 60, appendix A) and Methods 203A and 203C of this
appendix, with opacity readings taken at five second observation
intervals and two consecutive readings per plume beginning with the
first reading at zero seconds, in accordance with Method 203C,
sections 2.3.2. and 2.4.2 of this appendix. Conduct visible opacity
tests only on dry unpaved surfaces (i.e. when the surface is not
damp to the touch) and on days when average wind speeds do not
exceed 15 miles per hour (mph).
(i) Method 203A--Visual Determination of Opacity of Emissions From
Stationary Sources for Time-Arranged Regulations
Method 203A is virtually identical to EPA's Method 9 (40 CFR
Part 60 Appendix A) except for the data-reduction procedures, which
provide for averaging times other than 6 minutes. That is, using
Method 203A with a 6-minute averaging time would be the same as
following EPA Method 9 (40 CFR Part 60, Appendix A). Additionally,
Method 203A provides procedures for fugitive dust applications. The
certification procedures provided in section 3 are virtually
identical to Method 9 (40 CFR Part 60, Appendix A) and are provided
here, in full, for clarity and convenience.
1. Applicability and Principle
1.1 Applicability. This method is applicable for the
determination of the opacity of emissions from sources of visible
emissions for time-averaged regulations. A time-averaged regulation
is any regulation that requires averaging visible emission data to
determine the opacity of visible emissions over a specific time
period.
1.2 Principle. The opacity of emissions from sources of visible
emissions is determined visually by an observer qualified according
to the procedures of section 3.
2. Procedures
An observer qualified in accordance with section 3 of this
method shall use the following procedures for visually determining
the opacity of emissions.
2.1 Procedures for Emissions from Stationary Sources. These
procedures are not applicable to this section.
2.2 Procedures for Fugitive Process Dust Emissions. These
procedures are applicable for the determination of the opacity of
fugitive emissions by a qualified observer. The qualified field
observer should do the following:
[[Page 71311]]
2.2.1 Position. Stand at a position at least 5 meters from the
fugitive dust source in order to provide a clear view of the
emissions with the sun oriented in the 140-degree sector to the
back. Consistent as much as possible with maintaining the above
requirements, make opacity observations from a position such that
the line of vision is approximately perpendicular to the plume and
wind direction. As much as possible, if multiple plumes are
involved, do not include more than one plume in the line of sight at
one time.
2.2.2 Field Records. Record the name of the plant or site,
fugitive source location, source type [pile, stack industrial
process unit, incinerator, open burning operation activity, material
handling (transfer, loading, sorting, etc.)], method of control
used, if any, observer's name, certification data and affiliation,
and a sketch of the observer's position relative to the fugitive
source. Also, record the time, estimated distance to the fugitive
source location, approximate wind direction, estimated wind speed,
description of the sky condition (presence and color of clouds),
observer's position relative to the fugitive source, and color of
the plume and type of background on the visible emission observation
form when opacity readings are initiated and completed.
2.2.3 Observations. Make opacity observations, to the extent
possible, using a contrasting background that is perpendicular to
the line of vision. For roads, storage piles, and parking lots, make
opacity observations approximately 1 meter above the surface from
which the plume is generated. For other fugitive sources, make
opacity observations at the point of greatest opacity in that
portion of the plume where condensed water vapor is not present. For
intermittent sources, the initial observation should begin
immediately after a plume has been created above the surface
involved. Do not look continuously at the plume but, instead,
observe the plume momentarily at 15-second intervals.
2.3 Recording Observations. Record the opacity observations to
the nearest 5 percent every 15 seconds on an observational record
sheet. Each momentary observation recorded represents the average
opacity of emissions for a 15-second period.
2.4 Data Reduction for Time-Averaged Regulations. A set of
observations is composed of an appropriate number of consecutive
observations determined by the averaging time specified. Divide the
recorded observations into sets of appropriate time lengths for the
specified averaging time. Sets must consist of consecutive
observations; however, observations immediately preceding and
following interrupted observations shall be deemed consecutive. Sets
need not be consecutive in time and in no case shall two sets
overlap, resulting in multiple violations. For each set of
observations, calculate the appropriate average opacity.
3. Qualification and Testing
3.1 Certification Requirements. To receive certification as a
qualified observer, a candidate must be tested and demonstrate the
ability to assign opacity readings in 5 percent increments to 25
different black plumes and 25 different white plumes, with an error
not to exceed 15 percent opacity on any one reading and an average
error not to exceed 7.5 percent opacity in each category. Candidates
shall be tested according to the procedures described in paragraph
3.2. Any smoke generator used pursuant to paragraph 3.2 shall be
equipped with a smoke meter which meets the requirements of
paragraph 3.3. Certification tests that do not meet the requirements
of paragraphs 3.2 and 3.3 are not valid.
The certification shall be valid for a period of 6 months, and
after each 6-month period, the qualification procedures must be
repeated by an observer in order to retain certification.
3.2 Certification Procedure. The certification test consists of
showing the candidate a complete run of 50 plumes, 25 black plumes
and 25 white plumes, generated by a smoke generator. Plumes shall be
presented in random order within each set of 25 black and 25 white
plumes. The candidate assigns an opacity value to each plume and
records the observation on a suitable form. At the completion of
each run of 50 readings, the score of the candidate is determined.
If a candidate fails to qualify, the complete run of 50 readings
must be repeated in any retest. The smoke test may be administered
as part of a smoke school or training program, and may be preceded
by training or familiarization runs of the smoke generator during
which candidates are shown black and white plumes of known opacity.
3.3 Smoke Generator Specifications. Any smoke generator used for
the purpose of paragraph 3.2 shall be equipped with a smoke meter
installed to measure opacity across the diameter of the smoke
generator stack. The smoke meter output shall display in-stack
opacity, based upon a path length equal to the stack exit diameter
on a full 0 to 100 percent chart recorder scale. The smoke meter
optical design and performance shall meet the specifications shown
in Table A. The smoke meter shall be calibrated as prescribed in
paragraph 3.3.1 prior to conducting each smoke reading test. At the
completion of each test, the zero and span drift, shall be checked,
and if the drift exceeds 1 percent opacity, the
condition shall be corrected prior to conducting any subsequent test
runs. The smoke meter shall be demonstrated at the time of
installation to meet the specifications listed in Table A. This
demonstration shall be repeated following any subsequent repair or
replacement of the photocell or associated electronic circuitry
including the chart recorder or output meter, or every 6 months,
whichever occurs first.
3.3.1 Calibration. The smoke meter is calibrated after allowing
a minimum of 30 minutes warm-up by alternately producing simulated
opacity of 0 percent and 100 percent. When stable response at 0
percent or 100 percent is noted, the smoke meter is adjusted to
produce an output of 0 percent or 100 percent, as appropriate. This
calibration shall be repeated until stable 0 percent and 100 percent
readings are produced without adjustment. Simulated 0 percent and
100 percent opacity values may be produced by alternately switching
the power to the light source on and off while the smoke generator
is not producing smoke.
3.3.2 Smoke Meter Evaluation. The smoke meter design and
performance are to be evaluated as follows:
3.3.2.1 Light Source. Verify from manufacturer's data and from
voltage measurements made at the lamp, as installed, that the lamp
is operated within 5 percent of the nominal rated
voltage.
3.3.2.2 Spectral Response of Photocell. Verify from
manufacturer's data that the photocell has a photopic response;
i.e., the spectral sensitivity of the cell shall closely approximate
the standard spectral-luminosity curve for photopic vision which is
referenced in (b) of Table A.
3.3.2.3 Angle of View. Check construction geometry to ensure
that the total angle of view of the smoke plume, as seen by the
photocell, does not exceed 15 degrees. Calculate the total angle of
view as follows:
v = 2 tan-1 d/2L
Where:
v = total angle of view;
d = the photocell diameter + the diameter of the limiting aperture;
and
L = distance from the photocell to the limiting aperture.
The limiting aperture is the point in the path between the
photocell and the smoke plume where the angle of view is most
restricted. In smoke generator smoke meters, this is normally an
orifice plate.
3.3.2.4 Angle of Projection. Check construction geometry to
ensure that the total angle of projection of the lamp on the smoke
plume does not exceed 15 degrees. Calculate the total angle of
projection as follows:
p = 2 tan-1 d/2L
Where:
p = total angle of projection;
d = the sum of the length of the lamp filament + the diameter of the
limiting aperture; and
L = the distance from the lamp to the limiting aperture.
3.3.2.5 Calibration Error. Using neutral-density filters of
known opacity, check the error between the actual response and the
theoretical linear response of the smoke meter. This check is
accomplished by first calibrating the smoke meter according to 3.3.1
and then inserting a series of three neutral-density filters of
nominal opacity of 20, 50, and 75 percent in the smoke meter path
length. Use filters calibrated within 2 percent. Care
should be taken when inserting the filters to prevent stray light
from affecting the meter. Make a total of five nonconsecutive
readings for each filter. The maximum opacity error on any one
reading shall be 3 percent.
3.3.2.6 Zero and Span Drift. Determine the zero and span drift
by calibrating and operating the smoke generator in a normal manner
over a 1-hour period. The drift is measured by checking the zero and
span at the end of this period.
3.3.2.7 Response Time. Determine the response time by producing
the series of five simulated 0 percent and 100 percent opacity
values and observing the time required to reach stable response.
Opacity values of 0 percent and 100 percent may be simulated by
alternately switching the power to the light
[[Page 71312]]
source off and on while the smoke generator is not operating.
4. References
1. U.S. Environmental Protection Agency. Standards of
Performance for New Stationary Sources; appendix A; Method 9 for
Visual Determination of the Opacity of Emissions from Stationary
Sources. Final Rule. 39 FR 219. Washington, DC. U.S. Government
Printing Office. November 12, 1974.
2. Office of Air and Radiation. ``Quality Assurance Guideline
for Visible Emission Training Programs.'' EPA-600/S4-83-011. Quality
Assurance Division. Research Triangle Park, N.C. May 1982.
3. ``Method 9--Visible Determination of the Opacity of Emissions
from Stationary Sources.'' February 1984. Quality Assurance Handbook
for Air Pollution Measurement Systems. Volume III, section 3.1.2.
Stationary Source Specific Methods. EPA-600-4-77-027b. August 1977.
Office of Research and Development Publications, 26 West Clair
Street, Cincinnati, OH.
4. Office of Air Quality Planning and Standards. ``Opacity Error
for Averaging and Nonaveraging Data Reduction and Reporting
Techniques.'' Final Report-SR-1-6-85. Emission Measurement Branch,
Research Triangle Park, N.C. June 1985.
5. The U.S. Environmental Protection Agency. Preparation,
Adoption, and Submittal of State Implementation Plans. Methods for
Measurement of PM10 Emissions from Stationary Sources.
Final Rule. Federal Register. Washington, DC. U.S. Government
Printing Office. Volumes 55. No. 74. pps. 14246-14279. April 17,
1990.
(ii) Method 203C--Visual Determination of Opacity of Emissions From
Stationary Sources for Instantaneous Limitation Regulations
Method 203C is virtually identical to EPA's Method 9 (40 CFR
Part 60, Appendix A), except for the data-reduction procedures which
have been modified for application to instantaneous limitation
regulations. Additionally, Method 203C provides procedures for
fugitive dust applications which were unavailable when Method 9 was
promulgated. The certification procedures in section 3 are identical
to Method 9. These certification procedures are provided in Method
203A as well, and, therefore, have not been repeated in this method.
1. Applicability and Principle
1.1 Applicability. This method is applicable for the
determination of the opacity of emissions from sources of visible
emissions for instantaneous limitations. An instantaneous limitation
regulation is an opacity limit which is never to be exceeded.
1.2 Principle. The opacity of emissions from sources of visible
emissions is determined visually by a qualified observer.
2. Procedures
The observer qualified in accordance with section 3 of this
method shall use the following procedures for visually determining
the opacity of emissions.
2.1 Procedures for Emissions From Stationary Sources. Same as
2.1, Method 203A.
2.1.1 Position. Same as 2.1.1, Method 203A.
2.1.2 Field Records. Same as 2.1.2, Method 203A.
2.1.3 Observations. Make opacity observations at the point of
greatest opacity in that portion of the plume where condensed water
vapor is not present.
Do not look continuously at the plume. Instead, observe the
plume momentarily at the interval specified in the subject
regulation. Unless otherwise specified, a 15-second observation
interval is assumed.
2.1.3.1 Attached Steam Plumes. Same as 2.1.3.1, Method 203A.
2.1.3.2 Detached Steam Plumes. Same as 2.1.3.2, Method 203A.
2.2 Procedures for Fugitive Process Dust Emissions.
2.2.1 Position. Same as section 2.2.1, Method 203A.
2.2.2 Field Records. Same as section 2.2.2, Method 203A.
2.2.3 Observations.
2.2.3.1 Observations for a 15-second Observation Interval
Regulations. Same as section 2.2.3, Method 203A.
2.2.3.2 Observations for a 5-second Observation Interval
Regulations. Same as section 2.2.3, Method 203A, except, observe the
plume momentarily at 5-second intervals.
2.3 Recording Observations. Record opacity observations to the
nearest 5 percent at the prescribed interval on an observational
record sheet. Each momentary observation recorded represents the
average of emissions for the prescribed period. If a 5-second
observation period is not specified in the applicable regulation, a
15-second interval is assumed. The overall time for which recordings
are made shall be of a length appropriate to the regulation for
which opacity is being measured.
2.3.1 Recording Observations for 15-second Observation Interval
Regulations. Record opacity observations to the nearest 5 percent at
15-second intervals on an observational record sheet. Each momentary
observation recorded represents the average of emissions for a 15-
second period.
2.3.2 Recording Observations for 5-second Observation Interval
Regulations. Record opacity observations to the nearest 5 percent at
5-second intervals on an observational record sheet. Each momentary
observation recorded represents the average of emissions for 5-
second period.
2.4 Data Reduction for Instantaneous Limitation Regulations. For
an instantaneous limitation regulation, a 1-minute averaging time
will be used. Divide the observations recorded on the record sheet
into sets of consecutive observations. A set is composed of the
consecutive observations made in 1 minute. Sets need not be
consecutive in time, and in no case shall two sets overlap. Reduce
opacity observations by dividing the sum of all observations
recorded in a set by the number of observations recorded in each
set.
2.4.1 Data Reduction for 15-second Observation Intervals. Reduce
opacity observations by averaging four consecutive observations
recorded at 15-second intervals. Divide the observations recorded on
the record sheet into sets of four consecutive observations. For
each set of four observations, calculate the average by summing the
opacity of the four observations and dividing this sum by four.
2.4.2 Data Reduction for 5-second Observation Intervals. Reduce
opacity observations by averaging 12 consecutive observations
recorded at 5-second intervals. Divide the observations recorded on
the record sheet into sets of 12 consecutive observations. For each
set of 12 observations, calculate the average by summing the opacity
of the 12 observations and dividing this sum by 12.
3. Qualification and Test
Same as section 3, Method 203A.
TABLE A.--Smoke Meter Design and Performance Specifications
----------------------------------------------------------------------------------------------------------------
Parameter Specification
----------------------------------------------------------------------------------------------------------------
a. Light Source........................ Incandescent lamp operated at nominal rated voltage.
b. Spectral response of photocell...... Photopic (daylight spectral response of the human eye--Reference 4.1 of
section 4.)
c. Angle of view....................... 15 degrees maximum total angle
d. Angle of projection................. 15 degrees maximum total angle.
e. Calibration error................... 3 percent opacity, maximum.
f. Zero and span drift................. 1 percent opacity, 30 minutes.
g. Response time....................... 5 seconds.
----------------------------------------------------------------------------------------------------------------
B. Silt Content
Conduct the following test method to determine the silt loading
and silt content of unpaved road and unpaved parking lot surfaces.
(i) Collect a sample of loose surface material from an area 30
cm by 30 cm (1 foot by 1 foot) in size to a depth of approximately 1
cm or until a hard subsurface is reached, whichever occurs first.
Use a brush and dustpan or other similar device. Collect the sample
from a routinely-traveled portion of the surface which receives a
preponderance of vehicle traffic, i.e. as commonly evidenced by tire
tracks. Conduct sweeping slowly so
[[Page 71313]]
that fine surface material is not released into the air. Only
collect samples from surfaces that are not wet or damp due to
precipitation or dew.
(ii) Obtain a shallow, lightweight container and a scale with
readings in half ounce increments or less. Place the scale on a
level surface and zero it with the weight of the empty container.
Transfer the entire sample collected to the container, minimizing
escape of particles into the air. Weigh the sample and record its
weight.
(iii) Obtain and stack a set of sieves with the following
openings: 4 mm, 2 mm, 1 mm, 0.5 mm, and 0.25 mm. Place the sieves in
order according to size openings beginning with the largest size
opening at the top. Place a collector pan underneath the bottom
(0.25 mm) sieve. Pour the entire sample into the top sieve,
minimizing escape of particles into the air by positioning the
sieve/collector pan unit in an enclosed or wind barricaded area.
Cover the sieve/collector pan unit with a lid. Shake the covered
sieve/collector pan unit vigorously for a period of at least one (1)
minute in both the horizontal and vertical planes. Remove the lid
from the sieve/collector pan unit and disassemble each sieve
separately beginning with the largest sieve. As each sieve is
removed, examine it for a complete separation of material in order
to ensure that all material has been sifted to the finest sieve
through which it can pass. If not, reassemble and cover the sieve/
collector pan unit and shake it for period of at least one (1)
minute. After disassembling the sieve/collector pan unit, transfer
the material which is captured in the collector pan into the
lightweight container originally used to collect and weigh the
sample. Minimize escape of particles into the air when transferring
the material into the container. Weigh the container with the
material from the collector pan and record its weight. Multiply the
resulting weight by 0.38 if the source is an unpaved road or by 0.55
if the source is an unpaved parking lot to estimate silt loading.
Divide by the total sample weight and multiply by 100 to arrive at
the percent silt content.
(iv) As an alternative to conducting the procedure described
above in section I.B.(ii) and section I.B.(iii) of this appendix,
the sample (collected according to section I.B.(i) of this appendix)
may be taken to an independent testing laboratory or engineering
facility for silt loading (e.g. net weight < 200="" mesh)="" and="" silt="" content="" analysis="" according="" to="" the="" following="" test="" method="" from="" ``procedures="" for="" laboratory="" analysis="" of="" surface/bulk="" dust="" loading="" samples'',="" (fifth="" edition,="" volume="" i,="" appendix="" c.2.3="" ``silt="" analysis'',="" 1995),="" ap-42,="" office="" of="" air="" quality="" planning="" &="" standards,="" u.s.="" environmental="" protection="" agency,="" research="" triangle="" park,="" north="" carolina.="" 1.="" objective--several="" open="" dust="" emission="" factors="" have="" been="" found="" to="" be="" correlated="" with="" the="" silt="">< 200="" mesh)="" of="" the="" material="" being="" disturbed.="" the="" basic="" procedure="" for="" silt="" content="" determination="" is="" mechanical,="" dry="" sieving.="" for="" sources="" other="" than="" paved="" roads,="" the="" same="" sample="" which="" was="" oven-dried="" to="" determine="" moisture="" content="" is="" then="" mechanically="" sieved.="" 2.1="" procedure--select="" the="" appropriate="" 20-cm="" (8-in.)="" diameter,="" 5-="" cm="" (2-in.)="" deep="" sieve="" sizes.="" recommended="" u.="" s.="" standard="" series="" sizes="" are="" 3/8="" in.,="" no.="" 4,="" no.="" 40,="" no.="" 100,="" no.="" 140,="" no.="" 200,="" and="" a="" pan.="" comparable="" tyler="" series="" sizes="" can="" also="" be="" used.="" the="" no.="" 20="" and="" the="" no.="" 200="" are="" mandatory.="" the="" others="" can="" be="" varied="" if="" the="" recommended="" sieves="" are="" not="" available,="" or="" if="" buildup="" on="" 1="" particulate="" sieve="" during="" sieving="" indicates="" that="" an="" intermediate="" sieve="" should="" be="" inserted.="" 2.2="" obtain="" a="" mechanical="" sieving="" device,="" such="" as="" a="" vibratory="" shaker="" or="" a="" roto-tap=""> 1 without the tapping
function.
---------------------------------------------------------------------------
\1\ CFR part 60, App. A, Meth. 5, 2.1.2, footnote 2.
---------------------------------------------------------------------------
2.3 Clean the sieves with compressed air and/or a soft brush.
Any material lodged in the sieve openings or adhering to the sides
of the sieve should be removed, without handling the screen roughly,
if possible.
2.4 Obtain a scale (capacity of at least 1600 grams [g] or 3.5
lb) and record make, capacity, smallest division, date of last
calibration, and accuracy. (See Figure A)
2.5 Weigh the sieves and pan to determine tare weights. Check
the zero before every weighing. Record the weights.
2.6 After nesting the sieves in decreasing order of size, and
with pan at the bottom, dump dried laboratory sample (preferably
immediately after moisture analysis) into the top sieve. The sample
should weigh between 400 and 1600 g ( 0.9
and 3.5 lb). This amount will vary for finely textured materials,
and 100 to 300 g may be sufficient when 90% of the sample passes a
No. 8 (2.36 mm) sieve. Brush any fine material adhering to the sides
of the container into the top sieve and cover the top sieve with a
special lid normally purchased with the pan.
2.7 Place nested sieves into the mechanical sieving device and
sieve for 10 minutes (min). Remove pan containing minus No. 200 and
weigh. Repeat the sieving at 10-min intervals until the difference
between 2 successive pan sample weighings (with the pan tare weight
subtracted) is less than 3.0%. Do not sieve longer than 40 min.
2.8 Weigh each sieve and its contents and record the weight.
Check the zero before every weighing.
2.9 Collect the laboratory sample. Place the sample in a
separate container if further analysis is expected.
2.10 Calculate the percent of mass less than the 200 mesh screen
(75 micrometers [m]). This is the silt content.
Figure A. Example silt analysis form.
Silt Analysis
Dated: __________
By: ________________________
Sample No: ________ Sample Weight (after drying)
Material: ________
Pan + Sample: ____________
Pan: ____________
Split Sample Balance: ____________
Dry Sample: ______________
Make ____________ Capacity: ____________
Smallest Division ________
Final Weight ____________
% Silt = [Net Weight <200 mesh]=""> [Total Net Weight x 100]
=____%
Sieving
------------------------------------------------------------------------
Time: Start: Weight (Pan Only)
------------------------------------------------------------------------
Initial (Tare):
10 min:
20 min:
30 min:
40 min:
------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Final weight (screen +
Screen Tare weight (screen) sample) Net weight (sample) %
----------------------------------------------------------------------------------------------------------------
\3/8\ in.......................
4 mesh.........................
10 mesh........................
20 mesh........................
40 mesh........................
100 mesh.......................
140 mesh.......................
200 mesh.......................
Pan............................
----------------------------------------------------------------------------------------------------------------
(v) The silt loading and percent silt content for any given
unpaved road surface or unpaved parking lot surface shall be based
on the average of at least three (3) samples that are representative
of routinely-traveled portions of the road or parking lot surface.
In order to simplify the sieve test procedures in section I.B.(ii)
and section I.B.(iii) of this appendix, the three samples may be
combined as long as all material is sifted to the finest sieve
through which it can pass, each sample weighs within 1 ounce of the
other two samples, and the combined weight of the samples and unit
area from which they were collected is calculated and recorded
accurately.
[[Page 71314]]
II. Vacant Lots
The following test methods shall be used for determining whether
a vacant lot, or portion thereof, has a stabilized surface.
Should a disturbed vacant lot contain more than one type of
disturbance, soil, vegetation or other characteristics which are
visibly distinguishable, test each representative surface for
stability separately in random areas according to the test methods
in section II. of this appendix and include or eliminate it from the
total size assessment of disturbed surface area(s) depending upon
test method results. A vacant lot surface shall be considered
stabilized if any of the test methods in section II. of this
appendix indicate that the surface is stabilized such that the
conditions defined in paragraph (b)(16)(ii) of this section are met:
1. Visible Crust Determination
(i) Where a visible crust exists, drop a steel ball with a
diameter of 15.9 millimeters (0.625 inches) and a mass ranging from
16 to 17 grams from a distance of 30 centimeters (one foot) directly
above (at a 90 degree angle perpendicular to) the soil surface. If
blowsand is present, clear the blowsand from the surfaces on which
the visible crust test method is conducted. Blowsand is defined as
thin deposits of loose uncombined grains covering less than 50
percent of a vacant lot which have not originated from the
representative vacant lot surface being tested. If material covers a
visible crust which is not blowsand, apply the test method in
section II.2 of this appendix to the loose material to determine
whether the surface is stabilized.
(ii) A sufficient crust is defined under the following
conditions: once a ball has been dropped according to section
II.1.(i) of this appendix, the ball does not sink into the surface
so that it is partially or fully surrounded by loose grains and,
upon removing the ball, the surface upon which it fell has not been
pulverized so that loose grains are visible.
(iii) Conduct three tests, dropping the ball once per test,
within a survey area the size of one foot by one foot. The survey
area shall be considered sufficiently crusted if at least two out of
three tests meet the definition in section II.1.(ii) of this
appendix. Select at least two other survey areas that represent the
disturbed surface area and repeat this procedure. Whether a
sufficient crust covers the disturbed surface area shall be based on
a determination that all of the survey areas tested are sufficiently
crusted.
(iv) At any given site, the existence of a sufficient crust
covering one portion of a disturbed surface may not represent the
existence or protectiveness of a crust on another disturbed
surface(s). Repeat the visible crust test as often as necessary on
each representative disturbed surface area for an accurate
assessment of all disturbed surfaces at a given site.
2. Determination of Threshold Friction Velocity (TFV)
For disturbed surface areas that are not crusted or vegetated,
determine threshold friction velocity (TFV) according to the
following sieving field procedure (based on a 1952 laboratory
procedure published by W. S. Chepil).
(i) Obtain and stack a set of sieves with the following
openings: 4 millimeters (mm), 2 mm, 1 mm, 0.5 mm, and 0.25 mm. Place
the sieves in order according to size openings beginning with the
largest size opening at the top. Place a collector pan underneath
the bottom (0.25 mm) sieve. Collect a sample of loose surface
material from an area at least 30 cm by 30 cm in size to a depth of
approximately 1 cm using a brush and dustpan or other similar
device. Only collect soil samples from dry surfaces (i.e. when the
surface is not damp to the touch). Remove any rocks larger than 1 cm
in diameter from the sample. Pour the sample into the top sieve (4
mm opening) and cover the sieve/collector pan unit with a lid.
Minimize escape of particles into the air when transferring surface
soil into the sieve/collector pan unit. Move the covered sieve/
collector pan unit by hand using a broad, circular arm motion in the
horizontal plane. Complete twenty circular arm movements, ten
clockwise and ten counterclockwise, at a speed just necessary to
achieve some relative horizontal motion between the sieves and the
particles. Remove the lid from the sieve/collector pan unit and
disassemble each sieve separately beginning with the largest sieve.
As each sieve is removed, examine it for loose particles. If loose
particles have not been sifted to the finest sieve through which
they can pass, reassemble and cover the sieve/collector pan unit and
gently rotate it an additional ten times. After disassembling the
sieve/collector pan unit, slightly tilt and gently tap each sieve
and the collector pan so that material aligns along one side. In
doing so, minimize escape of particles into the air. Line up the
sieves and collector pan in a row and visibly inspect the relative
quantities of catch in order to determine which sieve (or whether
the collector pan) contains the greatest volume of material. If a
visual determination of relative volumes of catch among sieves is
difficult, use a graduated cylinder to measure the volume. Estimate
TFV for the sieve catch with the greatest volume using Table 1,
which provides a correlation between sieve opening size and TFV.
Table 1 (Metric Units).--Determination of Threshold Friction Velocity
(TFV)
------------------------------------------------------------------------
Opening TFV (cm/
Tyler Sieve No. (mm) s)
------------------------------------------------------------------------
5.................................................. 4 >100
10................................................. 2 100
18................................................. 1 76
35................................................. 0.5 58
60................................................. 0.25 43
Collector Pan...................................... ......... 30
------------------------------------------------------------------------
Collect at least three (3) soil samples which are representative
of the disturbed surface area, repeat the above TFV test method for
each sample and average the resulting TFVs together to determine the
TFV uncorrected for non-erodible elements.
(ii) Non-erodible elements are distinct elements on the
disturbed surface area that are larger than one (1) cm in diameter,
remain firmly in place during a wind episode and inhibit soil loss
by consuming part of the shear stress of the wind. Non-erodible
elements include stones and bulk surface material but do not include
flat or standing vegetation. For surfaces with non-erodible
elements, determine corrections to the TFV by identifying the
fraction of the survey area, as viewed from directly overhead, that
is occupied by non-erodible elements using the following procedure.
Select a survey area of one (1) meter by 1 meter. Where many non-
erodible elements lie on the disturbed surface area, separate them
into groups according to size. For each group, calculate the
overhead area for the non-erodible elements according to the
following equations:
(Average length) x (Average width) = Average Dimensions Eq. 1
(Average Dimensions) x (Number of Elements) = Overhead Area Eq.
2
Overhead Area of Group 1 + Overhead Area of Group 2 (etc.) = Total
Overhead Area Eq. 3
Total Overhead Area/2 = Total Frontal Area Eq. 4
(Total Frontal Area/Survey Area) x 100 = Percent Cover of Non-
erodible Elements Eq. 5
(Ensure consistent units of measurement, e.g. square meters or
square inches when calculating percent cover.)
Repeat this procedure on an additional two (2) distinct survey
areas representing a disturbed surface and average the results. Use
Table 2 to identify the correction factor for the percent cover of
non-erodible elements. Multiply the TFV by the corresponding
correction factor to calculate the TFV corrected for non-erodible
elements.
Table 2.--Correction Factors for Threshold Friction Velocity
------------------------------------------------------------------------
Percent cover of non-erodible elements Correction factor
------------------------------------------------------------------------
10%............................. 5
5% and < 10%....................="" 3="">< 5%="" and=""> 1%.................... 2
< 1%.......................................="" none.="" ------------------------------------------------------------------------="" 3.="" determination="" of="" flat="" vegetation="" cover="" flat="" vegetation="" includes="" attached="" (rooted)="" vegetation="" or="" unattached="" vegetative="" debris="" lying="" on="" the="" surface="" with="" a="" predominant="" horizontal="" orientation="" that="" is="" not="" subject="" to="" movement="" by="" wind.="" flat="" vegetation="" which="" is="" dead="" but="" firmly="" attached="" shall="" be="" considered="" equally="" protective="" as="" live="" vegetation.="" stones="" or="" other="" aggregate="" larger="" than="" one="" centimeter="" in="" diameter="" shall="" be="" considered="" protective="" cover="" in="" the="" course="" of="" conducting="" the="" line="" transect="" method.="" where="" flat="" vegetation="" exists,="" conduct="" the="" following="" line="" transect="" method.="" (i)="" stretch="" a="" one-hundred="" (100)="" foot="" measuring="" tape="" across="" a="" disturbed="" surface="" area.="" firmly="" anchor="" both="" ends="" of="" the="" measuring="" tape="" into="" the="" surface="" using="" a="" tool="" such="" as="" a="" screwdriver="" with="" the="" tape="" stretched="" taut="" and="" close="" to="" the="" soil="" surface.="" if="" vegetation="" exists="" in="" regular="" rows,="" place="" the="" tape="" diagonally="" (at="" approximately="" a="" 45="" degree="" angle)="" away="" from="" a="" parallel="" or="" perpendicular="" position="" to="" the="" vegetated="" rows.="" pinpoint="" an="" area="" the="" size="" of="" a="" \3/32\="" inch="" diameter="" brazing="" [[page="" 71315]]="" rod="" or="" wooden="" dowel="" centered="" above="" each="" one-foot="" interval="" mark="" along="" one="" edge="" of="" the="" tape.="" count="" the="" number="" of="" times="" that="" flat="" vegetation="" lies="" directly="" underneath="" the="" pinpointed="" area="" at="" one-foot="" intervals.="" consistently="" observe="" the="" underlying="" surface="" from="" a="" 90="" degree="" angle="" directly="" above="" each="" pinpoint="" on="" one="" side="" of="" the="" tape.="" do="" not="" count="" the="" underlying="" surface="" as="" vegetated="" if="" any="" portion="" of="" the="" pinpoint="" extends="" beyond="" the="" edge="" of="" the="" vegetation="" underneath="" in="" any="" direction.="" if="" clumps="" of="" vegetation="" or="" vegetative="" debris="" lie="" underneath="" the="" pinpointed="" area,="" count="" the="" surface="" as="" vegetated="" unless="" bare="" soil="" is="" visible="" directly="" below="" the="" pinpointed="" area.="" when="" 100="" observations="" have="" been="" made,="" add="" together="" the="" number="" of="" times="" a="" surface="" was="" counted="" as="" vegetated.="" this="" total="" represents="" the="" percent="" of="" flat="" vegetation="" cover="" (e.g.="" if="" 35="" positive="" counts="" were="" made,="" then="" vegetation="" cover="" is="" 35="" percent).="" if="" the="" disturbed="" surface="" area="" is="" too="" small="" for="" 100="" observations,="" make="" as="" many="" observations="" as="" possible.="" then="" multiply="" the="" count="" of="" vegetated="" surface="" areas="" by="" the="" appropriate="" conversion="" factor="" to="" obtain="" percent="" cover.="" for="" example,="" if="" vegetation="" was="" counted="" 20="" times="" within="" a="" total="" of="" 50="" observations,="" divide="" 20="" by="" 50="" and="" multiply="" by="" 100="" to="" obtain="" a="" flat="" vegetation="" cover="" of="" 40="" percent.="" (ii)="" conduct="" the="" above="" line="" transect="" test="" method="" an="" additional="" two="" (2)="" times="" on="" areas="" representative="" of="" the="" disturbed="" surface="" and="" average="" results.="" 4.="" determination="" of="" standing="" vegetation="" cover="" standing="" vegetation="" includes="" vegetation="" that="" is="" attached="" (rooted)="" with="" a="" predominant="" vertical="" orientation.="" standing="" vegetation="" which="" is="" dead="" but="" firmly="" rooted="" shall="" be="" considered="" equally="" protective="" as="" live="" vegetation.="" conduct="" the="" following="" standing="" vegetation="" test="" method="" to="" determine="" if="" 30="" percent="" cover="" or="" more="" exists.="" if="" the="" resulting="" percent="" cover="" is="" less="" than="" 30="" percent="" but="" equal="" to="" or="" greater="" than="" 10="" percent,="" then="" conduct="" the="" threshold="" friction="" velocity="" test="" in="" section="" ii.2="" of="" this="" appendix="" in="" order="" to="" determine="" whether="" the="" disturbed="" surface="" area="" is="" stabilized="" according="" to="" paragraph="" (b)(16)(ii)(e)="" of="" this="" section.="" (i)="" for="" standing="" vegetation="" that="" consists="" of="" large,="" separate="" vegetative="" structures="" (for="" example,="" shrubs="" and="" sagebrush),="" select="" a="" survey="" area="" representing="" the="" disturbed="" surface="" that="" is="" the="" shape="" of="" a="" square="" with="" sides="" equal="" to="" at="" least="" ten="" (10)="" times="" the="" average="" height="" of="" the="" vegetative="" structures.="" for="" smaller="" standing="" vegetation,="" select="" a="" survey="" area="" of="" three="" (3)="" feet="" by="" 3="" feet.="" (ii)="" count="" the="" number="" of="" standing="" vegetative="" structures="" within="" the="" survey="" area.="" count="" vegetation="" which="" grows="" in="" clumps="" as="" a="" single="" unit.="" where="" different="" types="" of="" vegetation="" exists="" and/or="" vegetation="" of="" different="" height="" and="" width="" exists,="" separate="" the="" vegetative="" structures="" with="" similar="" dimensions="" into="" groups.="" count="" the="" number="" of="" vegetative="" structures="" in="" each="" group="" within="" the="" survey="" area.="" select="" an="" individual="" structure="" within="" each="" group="" that="" represents="" the="" average="" height="" and="" width="" of="" the="" vegetation="" in="" the="" group.="" if="" the="" structure="" is="" dense="" (i.e.="" when="" looking="" at="" it="" vertically="" from="" base="" to="" top="" there="" is="" little="" or="" zero="" open="" air="" space="" within="" its="" perimeter),="" calculate="" and="" record="" its="" frontal="" silhouette="" area="" according="" to="" equation="" 6="" of="" this="" appendix.="" also="" use="" equation="" 6="" if="" the="" survey="" area="" is="" larger="" than="" nine="" square="" feet,="" estimating="" the="" average="" height="" and="" width="" of="" the="" vegetation.="" otherwise,="" use="" the="" procedure="" in="" section="" ii.4.(iii)="" of="" this="" appendix="" to="" calculate="" the="" frontal="" silhouette="" area.="" then="" calculate="" the="" percent="" cover="" of="" standing="" vegetation="" according="" to="" equations="" 7,="" 8="" and="" 9="" of="" this="" appendix.="" (ensure="" consistent="" units="" of="" measurement,="" e.g.="" square="" feet="" or="" square="" inches="" when="" calculating="" percent="" cover.)="" (iii)="" vegetative="" density="" factor.="" cut="" a="" single,="" representative="" piece="" of="" vegetation="" (or="" consolidated="" vegetative="" structure)="" to="" within="" 1="" cm="" of="" surface="" soil.="" using="" a="" white="" paper="" grid="" or="" transparent="" grid="" over="" white="" paper,="" lay="" the="" vegetation="" flat="" on="" top="" of="" the="" grid="" (but="" do="" not="" apply="" pressure="" to="" flatten="" the="" structure).="" grid="" boxes="" of="" one="" inch="" or="" one="" half="" inch="" squares="" are="" sufficient="" for="" most="" vegetation="" when="" conducting="" this="" procedure.="" using="" a="" marker="" or="" pencil,="" outline="" the="" shape="" of="" the="" vegetation="" along="" its="" outer="" perimeter="" according="" to="" figure="" b,="" c="" or="" d="" of="" this="" appendix,="" as="" appropriate.="" (note:="" figure="" c="" differs="" from="" figure="" d="" primarily="" in="" that="" the="" width="" of="" vegetation="" in="" figure="" c="" is="" narrow="" at="" its="" base="" and="" gradually="" broadens="" to="" its="" tallest="" height.="" in="" figure="" d,="" the="" width="" of="" the="" vegetation="" generally="" becomes="" narrower="" from="" its="" midpoint="" to="" its="" tallest="" height.)="" remove="" the="" vegetation="" and="" count="" and="" record="" the="" total="" number="" of="" gridline="" intersections="" within="" the="" outlined="" area,="" but="" do="" not="" count="" gridline="" intersections="" that="" connect="" with="" the="" outlined="" shape.="" there="" must="" be="" at="" least="" 10="" gridline="" intersections="" within="" the="" outlined="" area="" and="" preferably="" more="" than="" 20,="" otherwise,="" use="" smaller="" grid="" boxes.="" draw="" small="" circles="" (no="" greater="" than="" a="" \3/32\="" inch="" diameter)="" at="" each="" gridline="" intersection="" counted="" within="" the="" outlined="" area.="" replace="" the="" vegetation="" on="" the="" grid="" within="" its="" outlined="" shape.="" from="" a="" distance="" of="" approximately="" two="" feet="" directly="" above="" the="" grid,="" observe="" each="" circled="" gridline="" intersection.="" count="" and="" record="" the="" number="" of="" circled="" gridline="" intersections="" that="" are="" not="" covered="" by="" any="" piece="" of="" the="" vegetation.="" to="" calculate="" percent="" vegetative="" density,="" use="" equations="" 10="" and="" 11="" of="" this="" appendix.="" if="" percent="" vegetative="" density="" is="" equal="" to="" or="" greater="" than="" 30,="" use="" the="" equation="" (eq.="" 14,="" 15="" or="" 16)="" that="" matches="" the="" outline="" used="" to="" trace="" the="" vegetation="" (figure="" b,="" c="" or="" d)="" to="" calculate="" its="" frontal="" silhouette="" area.="" if="" percent="" vegetative="" density="" is="" less="" than="" 30,="" use="" equations="" 12="" and="" 13="" of="" this="" appendix="" to="" calculate="" the="" frontal="" silhouette="" area.="" (iv)="" within="" a="" disturbed="" surface="" area="" that="" contains="" multiple="" types="" of="" vegetation="" with="" each="" vegetation="" type="" uniformly="" distributed,="" results="" of="" the="" percent="" cover="" associated="" with="" the="" individual="" vegetation="" types="" may="" be="" added="" together.="" (v)="" repeat="" this="" procedure="" on="" an="" additional="" two="" (2)="" distinct="" survey="" areas="" representing="" the="" disturbed="" surface="" and="" average="" the="" results.="" height="" x="" width="Frontal" silhouette="" area="" eq.="" 6="" (frontal="" silhouette="" area="" of="" individual="" vegetative="" structure)="" x="" number="" of="" vegetation="" structures="" per="" group="Group" frontal="" silhouette="" area="" of="" group="" eq.="" 7="" frontal="" silhouette="" area="" of="" group="" 1="" +="" frontal="" silhouette="" area="" of="" group="" 2="" (etc.)="Total" frontal="" silhouette="" area="" eq.="" 8="" (total="" frontal="" silhouette="" area/survey="" area)="" x="" 100="Percent" cover="" of="" standing="" vegetation="" eq.="" 9="" [(number="" of="" circled="" gridlines="" within="" the="" outlined="" area="" counted="" that="" are="" not="" covered="" by="" vegetation="" total="" number="" of="" gridline="" intersections="" within="" the="" outlined="" area)="" x="" 100]="Percent" open="" space="" eq.="" 10="" 100="Percent" open="" space="Percent" vegetative="" density="" eq.="" 11="" percent="" vegetative="" density/100="Vegetative" density="" eq.="" 12="" billing="" code="" 6560-50-p="" [graphic]="" [tiff="" omitted]="" tr21de99.000="" [[page="" 71316]]="" [graphic]="" [tiff="" omitted]="" tr21de99.001="" [[page="" 71317]]="" billing="" code="" 6560-50-c="" iii.="" alternative="" test="" methods="" alternative="" test="" methods="" may="" be="" used="" upon="" obtaining="" the="" written="" approval="" of="" the="" epa.="" [fr="" doc.="" 99-32760="" filed="" 12-20-99;="" 8:45="" am]="" billing="" code="" 6560-50-p="">